The present disclosure relates to a sheet feed device for feeding sheets one by one, and an image forming apparatus including the sheet feed device.
Conventionally, there has been known, as a sheet feed device for feeding sheets one by one, a sheet feed device attached to an image forming apparatus. The sheet feed device is composed of a pick-up roller, a sheet feed roller, and a retard roller that are provided in an apparatus main body of the image forming apparatus, as well as a sheet feed cassette that is attachable to and detachable from the apparatus main body. The sheet feed cassette stores the sheets. When the pick-up roller is rotated, a sheet is picked up from the sheet feed cassette and is fed in a sheet conveyance direction.
The sheet fed by the pick-up roller enters a sheet feed nip portion that is formed between the sheet feed roller and the retard roller. The sheet is further conveyed toward the downstream in the sheet conveyance direction, by the rotation of the sheet feed roller.
Conventionally, the sheet feed cassette is attached to the apparatus main body by being inserted into the apparatus main body in a predetermined attachment direction. After the sheet feed cassette is attached to the apparatus main body, it is locked by a lock mechanism provided in the apparatus main body. This prevents the sheet feed cassette from being pulled out by mistake while a sheet is being fed.